A lead acid battery is an inexpensive and highly reliable rechargeable battery, and thus, has been widely used for a vehicle, a power source of an electric vehicle such as a golf cart, or an industrial device such as an uninterruptible power supply (UPS) device and the like.
In general, a lead acid battery uses a sulfuric acid solution, which is strong acid, as an electrolyte, and thus, a substrate for the lead acid battery needs to be made of a material which is resistance to corrosion. Accordingly, lead and a lead alloy that resist sulfuric acid have been commonly used as the substrate material. The substrate for the lead acid battery is generally manufactured by casting, rolling expansion, rolling press, and the like. However, a relatively small amount of alloy is used in the lead alloy, and the lead alloy is not suitable as a material or light-weighted substrate since the lead alloy is used for enhancing the resistance to corrosion or improving strength instead of being used for reducing weight.
A constituent material that forms the lead acid battery, such as a substrate, an active material, and the like are made of lead having high density such that the lead acid battery is heavy compared to other rechargeable batteries. A number of methods have been developed to reduce battery weight, for example, a method for manufacturing a substrate by lead-plating a light-weighted metal (e.g., aluminum and the like) and a method for manufacturing foam-type porous substrate. The method of lead-plating the light-weighted metal may significantly reduce the weight of the substrate. However, this method cannot be used in welding of polarity group for the battery such that the substrate manufactured by lead-plating light-weighted metal is commercially available. In case of the foam-type substrate, the foam-type substrate cannot be used because another active material that is different from an existing active material needs to be developed and the shape of the battery changes, and thereby, an additional technique for design modification and development of is necessary.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.